Many industries have the need to remove dissolved gases in liquids, for example, to protect a downstream process or piece of equipment.
Oxygen, carbon dioxide, reactive gas, and other gases dissolved in water, solutions, or other liquids can adversely affect many processes. For instance, in the industrial, pharmaceutical, or semiconductor industry, delivering water having low levels of dissolved gases leads to longer equipment life, reduced maintenance, and improved process quality.
Degasifying a liquid can be achieved by using devices such as:                open-air heated tanks for partial removal of dissolved gas;        systems for holding a contaminated liquid under a partial vacuum;        scrubbers, wherein a liquid contaminated with undesired gases are sprayed to form drops or spread on high-surface area configurations;        employing a membrane of separation cells;        exposing the liquids to ultrasonic waves; and        inducing hydrodynamic cavitation in the liquid, while maintaining a negative pressure within the volume in which the liquid is confined.        
U.S. Pat. No. 5,064,449 describes a method of degassing a fluid flow which includes locating a vortex valve having a vortex chamber with radial inlet, axial outlet, and tangential control ports in the fluid-flow line, regulating the pressure drop across the vortex chamber to cause cavitation with the release of dissolved gases in the flow at the outlet and removing the gases from the fluid flow.
U.S. Pat. No. 5,749,945 describes inline gas-dissolution devices that use cavitating venturi for removing micro-bubbles of dissolved gases from liquid.
Other patents such as U.S. Pat. Nos. 4,261,521, 5,435,913, 6,649,059, and 7,651,621 disclose a vortex-nozzle assembly constructed with a pair of vortex nozzles positioned within a housing in an opposed relationship. As fluid is forced spirally out of each vortex tube, centrifugal energy flattens a circular section of fluid against the side of the tapered vortex tube. This action accelerates the fluid as it spirals out toward the exit, creating a void inside the vortex tube chamber. When the fluid exits the walls of the vortex tube, it accelerates radially forming a hollow fluid cone. The hollow fluid cone from one vortex nozzle impacts with the hollow fluid cone from the other vortex nozzle inside the housing, which forms a liquid lined, closed chamber. This closed chamber develops a substantial cavitation vacuum due to the void caused by the centrifugal energy of the vortex. The energy from the impact of the two hollow fluid cones in the presence of this substantial vacuum effects changes to the fluid.
WO2007/020296 discloses a hydrodynamic cavitation degasifier, particularly a deaerator, which creates a degasifier as well as a degasifying method using the components known from cavitation mixers.
Other types of cavitation methods and devices for deaeration can be used such as the apparatus disclosed in U.S. Patent Publication No. 2003/0111429.
Although all of these devices have benefits, there are numerous problems remaining in the development of a reliable device for the removal of gases from liquids in a continuous mode.